Gears of War for me, I've never really cared for Halo even when it was good.

I'm not sure I'd say its the ugliest I've seen (that'd be maybe Fallout 3 or Watchdogs on PS3/360/Wii U) but yeah it wasn't pretty. X did a lot more with a lot less.

Halo by far. It was revolutionary for the genre on consoles. It also has always had much much better MP. Gameplay wise it’s also been more consistent and more varied over its games than Gears imho.

I did a complete play through of Gears and Halo five or six years ago on this site and made threads about them. Gears definitely has lower lows imho. Guardians is probably the worst game in either series, though. Worst mainline game, anyway.

I would give Gears the edge in the “other” games. Gears Tactics > Halo Wars > Halo Wars 2

It has to be Gears. I love some of the old Halo games, especially 2 and Reach, but the first Gears of War is at least as good, and the series never dropped as much in quality as Halo.

Gears is much more consistent in quality, while Halo hits more pronounced highs and lows. But Halo's highs are much higher than Gears' are IMO.

Halo CE is still one of my top three games ever, Halo 3 and ODST qualify for my Top 50, and Reach was great. However, Halo 2 had worse level designs, unbalanced and often cheap difficulty (esp. on Legendary), and even worse balancing in multiplayer, with numerous glitches to boot, but it did have the best map design of any Halo MP experience, and the campaign's narrative was perhaps my favorite in the series. Halo 4, though not a bad game, was the worst in the series IMO in terms of campaign. Halo 5 was an improvement for its campaign, at least in terms of level and encounter design, but the multiplayer was the worst in the series for me. Halo Infinite is just an inconsistent game itself. The linear interior levels and certain individual missions in its campaign were great, but the open world was just as bog-standard paint-by-numbers as 99% of open-world games, with a map dotted by repetitive side objectives, which while technically optional are essential for you to access fast-travel points and earn enough XP (called "Valor" in the game) to unlock weapons and vehicles in the armories at said FTPs. Infinite's multiplayer is solid in the sense of moment-to-moment combat, but suffers from overly restrictive SBMM, which makes nearly every match, even in unranked social matches, feels overly sweaty.

Meanwhile, I can play any Gears game and feel just as home in one as the other. There's been some tweaks and additions to the gameplay over the past 20 years, but the moment-to-moment combat generally feels the same game to game. It's a solid cover-based third-person shooter series with an interesting world and solid visuals. However, not one of the games I would consider as being close to the high points in Halo.